Field of the Invention
The invention relates to a fan clutch, in particular for connecting a fan of a cooling system to drive, such as an engine, in particular a motor vehicle engine, in particular for a motor vehicle.
Description of the Background Art
Fans are known, for example, in the form of axial fans and are used in motor vehicles for engine cooling, in particular in order to provide the engine compartment and the radiator with a sufficient quantity of air for cooling. This can be important when the vehicle is moving slowly or at standstill, as, particularly in these operating situations, the flow speed of the air and therefore the quantity of air can be too low due to the low vehicle speed.
The fan is connected to the engine of the motor vehicle by a fan clutch and is typically driven by means of the engine.
An axial fan for a radiator of a motor vehicle engine with a fan clutch, the fan hub of which is fixed by means of a fan flange on a clutch housing of a liquid friction clutch while leaving an annular gap, is disclosed in DE 44 45 671, which corresponds to U.S. Pat. No. 5,645,401, which is incorporated herein by reference. The liquid friction clutch can be driven by a drive part of the motor vehicle engine. An air guide ring, which has an arc-shaped profile which is axially opposed to the flow direction and curved radially inwards, is provided on the fan hub on an inlet side referred to the flow direction of the air flow.
A liquid friction clutch for a motor vehicle fan is disclosed in DE 10 2004 008 861 A1, which corresponds to U.S. Pat. No. 7,246,691, which is incorporated herein by reference. The clutch has at least one rotatably mounted shaft, on which is mounted at least one input drive body in a fixed rotational relationship. A clutch region, which accommodates a viscous fluid and by this means is able to transmit a torque between the input drive body and the output drive body, is provided between the input drive body and the output drive body.
DE 10 2008 035 185 A1, which corresponds to U.S. Pat. No. 8,408,371, which is incorporated herein by reference, and which relates to a fan clutch to which a fan is releasably fixed by means of a flange ring. The fan clutch has a housing comprising a first front housing part and a second rear housing part to which the flange ring can be fixed by means of connecting elements.